Sectional ingot molds are known in the prior art. U.S. Pat. No. 496,736 issued May 2, 1893 to C. Hodgson and U.S. Pat. No. 1,224,277 issued May 1, 1917 to F. Clarke, are examples of known sectional mold constructions. U.S. Pat. Nos. 354,742 issued Dec. 21, 1886 to J. Sabold, and British Pat. No. 13446 of A.D. 1900 in the name of Stephen Appleby, et al. and entitled "Improvements In or Connected With Ingot Molds", disclose sectional mold arrangements embodying means for relieving stress on the fastening bolts thereof due to the expansion of the molten metal. However, such prior art sectional molds have not always been satisfactory, due at least in part to oftentimes leakage of molten materials occurring between the mold sections during the pouring of the molten metal into the mold cavity and subsequent solidification of the metal, or due to the complexity and/or costs of such arrangements.
H. S. Lee and Amos E. Chaffee in U.S. Pat. No. 1,584,954, issued May 18, 1926 identified Permanent Mold Distortion and its control by using thermally responsive insert elements to effect control of a permanent mold leaking molten metal along the parting line and to avert distortion or a bowing action of the mold by placing higher or lower coefficient of expansion metals in position in the mold to resist the inward or outward movement of the mold thus directly effecting the casting being formed and produced by the permanent mold.
U.S. Pat. No. 158,696 to Foster et al. discloses a sectional mold in conjunction with spring-loaded bolts to provide for lateral expansion of the mold sections relative to one another during the expansive force of the molten metal poured into the mold.
To this and other prior art involving sectional molds, none have possessed fastener means for connecting mold wall sections together to form a mold cavity, while providing for automatic compensation, and including memory, to allow for expansion and retraction of the mold assembly sections when molten metal is poured into the ingot mold by providing for expeditious expansion of the mold sections with respect to one another while aiding in sealing the mold sections from leakage of molten metal during the pouring and cooling of the ingot in the mold.
Additional disclosures of the prior art of both sectional and one piece cast ingot mold and ingot assemblies reveal exhaustive patent work and issuance of over 80 patents by Emiel Gathmann beginning with U.S. Pat. No. 921,972 issued May 18, 1909 through to U.S. Pat. No. 2,290,804, issued July 21, 1942. Patents were issued almost every year by Gathmann and some years had two patents or more issued, indicating great in-depth knowledge and work on ingot molds and mold assemblies for over 34 years. From this and other patent endeavors no solution was found to the problem of extending ingot mold life and preventing mold leakage while simplifying ingot mold production by sectionalizing, and allowing for automatic expansion and retraction of mold sections during pouring of molten metal into the mold and the subsequent cooling cycle, as taught in the present application.